1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Windfarm PowerMac thermal control.
4 *
5 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
6 * <benh@kernel.crashing.org>
7 */
8
9 #ifndef __WINDFARM_H__
10 #define __WINDFARM_H__
11
12 #include <linux/kref.h>
13 #include <linux/list.h>
14 #include <linux/module.h>
15 #include <linux/notifier.h>
16 #include <linux/device.h>
17
18 /* Display a 16.16 fixed point value */
19 #define FIX32TOPRINT(f) (((s32)(f)) >> 16),(((((s32)(f)) & 0xffff) * 1000) >> 16)
20
21 /*
22 * Control objects
23 */
24
25 struct wf_control;
26
27 struct wf_control_ops {
28 int (*set_value)(struct wf_control *ct, s32 val);
29 int (*get_value)(struct wf_control *ct, s32 *val);
30 s32 (*get_min)(struct wf_control *ct);
31 s32 (*get_max)(struct wf_control *ct);
32 void (*release)(struct wf_control *ct);
33 struct module *owner;
34 };
35
36 struct wf_control {
37 struct list_head link;
38 const struct wf_control_ops *ops;
39 const char *name;
40 int type;
41 struct kref ref;
42 struct device_attribute attr;
43 void *priv;
44 };
45
46 #define WF_CONTROL_TYPE_GENERIC 0
47 #define WF_CONTROL_RPM_FAN 1
48 #define WF_CONTROL_PWM_FAN 2
49
50
51 /* Note about lifetime rules: wf_register_control() will initialize
52 * the kref and wf_unregister_control will decrement it, thus the
53 * object creating/disposing a given control shouldn't assume it
54 * still exists after wf_unregister_control has been called.
55 */
56 extern int wf_register_control(struct wf_control *ct);
57 extern void wf_unregister_control(struct wf_control *ct);
58 extern int wf_get_control(struct wf_control *ct);
59 extern void wf_put_control(struct wf_control *ct);
60
wf_control_set_max(struct wf_control * ct)61 static inline int wf_control_set_max(struct wf_control *ct)
62 {
63 s32 vmax = ct->ops->get_max(ct);
64 return ct->ops->set_value(ct, vmax);
65 }
66
wf_control_set_min(struct wf_control * ct)67 static inline int wf_control_set_min(struct wf_control *ct)
68 {
69 s32 vmin = ct->ops->get_min(ct);
70 return ct->ops->set_value(ct, vmin);
71 }
72
wf_control_set(struct wf_control * ct,s32 val)73 static inline int wf_control_set(struct wf_control *ct, s32 val)
74 {
75 return ct->ops->set_value(ct, val);
76 }
77
wf_control_get(struct wf_control * ct,s32 * val)78 static inline int wf_control_get(struct wf_control *ct, s32 *val)
79 {
80 return ct->ops->get_value(ct, val);
81 }
82
wf_control_get_min(struct wf_control * ct)83 static inline s32 wf_control_get_min(struct wf_control *ct)
84 {
85 return ct->ops->get_min(ct);
86 }
87
wf_control_get_max(struct wf_control * ct)88 static inline s32 wf_control_get_max(struct wf_control *ct)
89 {
90 return ct->ops->get_max(ct);
91 }
92
93 /*
94 * Sensor objects
95 */
96
97 struct wf_sensor;
98
99 struct wf_sensor_ops {
100 int (*get_value)(struct wf_sensor *sr, s32 *val);
101 void (*release)(struct wf_sensor *sr);
102 struct module *owner;
103 };
104
105 struct wf_sensor {
106 struct list_head link;
107 const struct wf_sensor_ops *ops;
108 const char *name;
109 struct kref ref;
110 struct device_attribute attr;
111 void *priv;
112 };
113
114 /* Same lifetime rules as controls */
115 extern int wf_register_sensor(struct wf_sensor *sr);
116 extern void wf_unregister_sensor(struct wf_sensor *sr);
117 extern int wf_get_sensor(struct wf_sensor *sr);
118 extern void wf_put_sensor(struct wf_sensor *sr);
119
wf_sensor_get(struct wf_sensor * sr,s32 * val)120 static inline int wf_sensor_get(struct wf_sensor *sr, s32 *val)
121 {
122 return sr->ops->get_value(sr, val);
123 }
124
125 /* For use by clients. Note that we are a bit racy here since
126 * notifier_block doesn't have a module owner field. I may fix
127 * it one day ...
128 *
129 * LOCKING NOTE !
130 *
131 * All "events" except WF_EVENT_TICK are called with an internal mutex
132 * held which will deadlock if you call basically any core routine.
133 * So don't ! Just take note of the event and do your actual operations
134 * from the ticker.
135 *
136 */
137 extern int wf_register_client(struct notifier_block *nb);
138 extern int wf_unregister_client(struct notifier_block *nb);
139
140 /* Overtemp conditions. Those are refcounted */
141 extern void wf_set_overtemp(void);
142 extern void wf_clear_overtemp(void);
143
144 #define WF_EVENT_NEW_CONTROL 0 /* param is wf_control * */
145 #define WF_EVENT_NEW_SENSOR 1 /* param is wf_sensor * */
146 #define WF_EVENT_OVERTEMP 2 /* no param */
147 #define WF_EVENT_NORMALTEMP 3 /* overtemp condition cleared */
148 #define WF_EVENT_TICK 4 /* 1 second tick */
149
150 /* Note: If that driver gets more broad use, we could replace the
151 * simplistic overtemp bits with "environmental conditions". That
152 * could then be used to also notify of things like fan failure,
153 * case open, battery conditions, ...
154 */
155
156 #endif /* __WINDFARM_H__ */
157